asp.net2.0 上傳圖片(FileUpload控制元件) 並生成縮圖

記錄，備忘：

（1）

using System.IO; //新增

（2）

在頁面上放入一個FileUpload控制元件，id為“FileUpload1”，和一個“上傳”按鈕，id為“btnUpload”。

///

///

"上傳"按鈕
///
///
///
protected voidbtnUpload_Click(objectsender, EventArgse)
{
    stringserverPath = Server.MapPath("~/images/product");//設定圖片路徑

    if(this.FileUpload1.HasFile)
    {
        stringname=FileUpload1.FileName;
        stringfName = this.txtImageName.Text;
        if(string.IsNullOrEmpty(fName))
        {
            fName = name;
        }
        stringtype = fName.Substring(fName.LastIndexOf(".") + 1).ToLower();           
        if(type == "jpg"|| type == "png"|| type == "bmp"|| type == "gif"|| type == "jpeg")
        {
            UpLoadImage(serverPath,fName);//執行上傳圖片，並生成縮圖
        }
        else
       {
            HttpContext.Current.Response.Write(");
            return;
        }
    }
    else
   {
        HttpContext.Current.Response.Write("

alert('請選擇要上傳的檔案')

");
        return;
    }
    HttpContext.Current.Response.Write("

alert('檔案上傳成功')

");
}

///

///

執行上傳圖片操作，並生成縮圖
///
///
///
private voidUpLoadImage(stringserverPath, stringfName)
{
    if(!File.Exists(serverPath))
    {
         Directory.CreateDirectory(serverPath);
         Directory.CreateDirectory(serverPath + "_thumb");
    }
    stringfPath = serverPath + "\\"+ fName;//檔案實際路徑

    Stringtpath = serverPath + "_thumb\\"+ fName;//縮圖路徑 

    if(!File.Exists(tpath) && !File.Exists(fPath))
    {       
         this.FileUpload1.SaveAs(fPath);//上傳到圖片路徑       
         ImageClass.MakeThumbnail(fPath, tpath, 180, 117, "w"); //呼叫ImageClass類的MakeThumbnail()方法，生成縮圖
         this.myImage.ImageUrl = "~/images/product_thumb"+ "\\"+ fName;
    }
    else
   {
         HttpContext.Current.Response.Write(");
         return;
    }
}

（3）ImageClass類（轉，網址忘記了）

//add
usingSystem.Data;
usingSystem.Configuration;
usingSystem.Web.UI;
usingSystem.IO;

///

///

生成縮圖
///
/// 源圖路徑（物理路徑）
/// 縮圖路徑（物理路徑）
/// 縮圖寬度
/// 縮圖高度
/// 生成縮圖的方式 
public static voidMakeThumbnail(stringoriginalImagePath, stringthumbnailPath, intwidth, intheight, stringmode)
{
    System.Drawing.ImageoriginalImage = System.Drawing.Image.FromFile(originalImagePath);

    inttowidth = width;
    inttoheight = height;

    intx = 0;
    inty = 0;
    intow = originalImage.Width;
    intoh = originalImage.Height;

    if(ow < towidth && oh < toheight)
    {
        originalImage.Save(thumbnailPath);
    }
    else
   {

        switch(mode.ToUpper())
        {
            case"HW"://指定高寬縮放（可能變形）         
                break;
            case"W"://指定寬，高按比例           
                toheight = originalImage.Height * width / originalImage.Width;
                break;
            case"H"://指定高，寬按比例
                towidth = originalImage.Width * height / originalImage.Height;
                break;
            case"CUT"://指定高寬裁減（不變形）         
                if((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
                {
                    h = originalImage.Height;
                    w = originalImage.Height * towidth / toheight;
                    y = 0;
                    x = (originalImage.Width - ow) / 2;
                }
                else
               {
                    w = originalImage.Width;
                    h = originalImage.Width * height / towidth;
                    x = 0;
                    y = (originalImage.Height - oh) / 2;
                }
                break;
            case"AUTO": //自動適應高度
                if(ow > oh)
                {
                    //newwidth = 200;
                   toheight = (int)((double)oh / (double)ow * (double)towidth);
                }
                else
               {
                    //newheight = 200;
                   towidth = (int)((double)ow / (double)oh * (double)toheight);
                }
                break;
            default:
                break;
        }

        //新建一個bmp圖片
        System.Drawing.Imagebitmap = newSystem.Drawing.Bitmap(towidth, toheight);

        //新建一個畫板
        System.Drawing.Graphicsg = System.Drawing.Graphics.FromImage(bitmap);

        //設定高質量插值法
        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

        //設定高質量,低速度呈現平滑程度
        g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

        //清空畫布並以透明背景色填充
        g.Clear(System.Drawing.Color.Transparent);

        //在指定位置並且按指定大小繪製原圖片的指定部分
        g.DrawImage(originalImage, newSystem.Drawing.Rectangle(0, 0, towidth, toheight),
            newSystem.Drawing.Rectangle(x, y, ow, oh),
            System.Drawing.GraphicsUnit.Pixel);

        try
       {
            //以jpg格式儲存縮圖
            bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);

        }
        catch(System.Exceptione)
        {
            throwe;
        }
        finally
       {

            bitmap.Dispose();
            g.Dispose();
        }
    }
    originalImage.Dispose();
}

來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/12639172/viewspace-626021/，如需轉載，請註明出處，否則將追究法律責任。